1. Field of the Invention
Exemplary embodiments of the present invention relate to a pedal simulator capable of allowing a pedal feeling of a brake to be similar to an existing brake system.
2. Description of the Related Art
In general, a brake-by-wire system performs braking of a vehicle in such a manner that, without mechanical connection between a driver and a braking wheel, an electric caliper located at each vehicle wheel receives a signal from an ECU of the brake-by-wire system and catches a disc located at each vehicle wheel.
Since this brake-by-wire system has a pedal effort characteristic as a pedal feeling felt by a driver during pedal operation of a hydraulic brake system mechanically connected, namely a characteristic which may not realize hysteresis depending upon reaction meaning a physical energy loss together with formation of a nonlinear pedal effort mainly caused by input/output characteristics generated from a booster, there is a need for a separate device to provide a driver with a proper pedal feeling.
Such a system is wholly equipped with an electric device capable of identifying pedal operation of a driver, together with, for example, a mechanical device to provide a driver with a proper pedal feeling, and is typically referred to as a pedal simulator.
Such a pedal simulator is aimed principally at providing a pedal feeling similar to an existing brake system.
Korean Unexamined Patent Application Publication No. 10-2000-0048717 discloses a pedal simulator as a specific example of the conventional pedal simulator.
The pedal simulator buffers therein a piston using one coil spring as a buffer member. However, there is a problem in that such a single buffer member simply indicates a pedal feeling of a brake only as a one-stage linear form.
To improve this, there has been proposed a pedal simulator structure of realizing a nonlinear pedal feeling by applying a plurality of springs and a plurality of dampers corresponding thereto. However, this pedal simulator structure has many problems such as complexity of the structure, an increase of manufacturing costs, and the like.